The projects of the Program Project each investigate different aspects of follicle structure, function and development. The purpose of Core B is to provide the services necessary to fully describe the overt and subtle changes in follicle populations that accompany alterations in specific gene expression patterns throughout the life span of the animal. The Ovarian Procurement, Processing and Analysis Core has three main components. First, to acquire gonadal tissue and serum samples from normal and mutant mice or rats in a standardized manner. Second, to preserve and process the tissue using established protocols ensuring high quality, consistent material for analysis. Finally, the Core will provide analytical services including histomorphometry (follicle counts, follicle and oocyte size, presence and structure of theca, stroma, vasculature), histopathology, and gene or gene product analysis. In addition to the provision of services associated with the histomorphometry of the ovary, the Core will also provide access to state-of-the-art tissue based technology needs that will extend the capabilities of each of the projects in significant ways. As new methods are developed, the Core will be in an excellent position to adapt novel pathology or histology-related techniques to the unique environment of the rodent ovary. Attention to developments in the field of tissue-based research will place the Core at the forefront of gonadal biology. The Core will accelerate the rapid pace of discovery that is anticipated by each of the projects. By providing highly trained technologists who are experts at the processing and analysis of the gonad, investigators will be able to identify and inspect subtle changes in follicle dynamics within discrete populations of follicles which otherwise might be missed by casual evaluation. Because it will concern itself with the ovary, the Core performs services that are unique and will serve to make routine the analysis of complex phenotypes that arise as a consequence of gonadal specific gene manipulations.